Preheat the oven to 375°F (190°C). Line or use a rimmed baking sheet.
Wipe the mushroom caps clean with a damp cloth or paper towel. Remove and discard (or reserve) the stems. Place the caps stem-side up on the baking sheet, spaced evenly.
Ensure the cream cheese is softened. In a medium bowl, combine the crab meat, softened cream cheese, chopped parsley, chopped green onions, grated Parmesan cheese, and Stone House Seasoning. Mix until evenly combined.
Divide the crab mixture evenly among the mushroom caps and spoon it into each cap, mounding slightly.
Evenly sprinkle the 1 cup panko over the tops of the stuffed mushrooms, pressing lightly so the crumbs adhere.
Bake on the center oven rack for 20 minutes, or until the mushrooms are tender and the filling is heated through and the panko is lightly golden.
Remove from the oven, let rest 2–3 minutes, then serve warm.